Sanding machine



Patented May 21, 1929.

UNITED STATES PATENT OFFICE.

.rosnrn n. GERETSCHLAEGER AND FRANK '1. oLAax, on ST. PAUL, MINNESOTA.

SANDING MACHINE.

Application filed January 17, 1928. Serial No. 247,387.

Our invention relates to a sand-papering machine particularly adapted for sand papering and scraping wooden floors and the main object of the invention is to provide a simple and highly eflicicnt machine for said purpose. 7 I

Among its advantages is a construction such that a floor may be scraped clear right up close to a wall or base board. Ourma'chine involves a new principle in its vibrating mechanism, is alsoof a broad scope of usefulness as provision is made for a scraper attachment having metal scrapers. Other objects and advantages will appear in the following specificationreference being had to the accompanying drawing, in which,

Fig. 1 is a top or plan View of our improved sanding machine.

Fig. 2 is a left side elevation of the sanding machine with a suction device added.

Fig. 3 is atransverse sectional view looking forward toward the motor, as on line 33 in 2. r Fig. 4 is a side elevation'and Fig. 5 a frag- 2 mentary bottom view of a scraper attachment for our sanding machine, both views includ ing a portion of the base plate of our machine. Referring to the drawing by reference numerals, our device comprises two base plates, one for the motor and the other for floor contact, of which plates the motor plate is designated 10, and is of elongated quadrangular form with its opposite longitudinal edges tongued as 10 11 is a suitable electric motor mounted at 12 on the front part of platform 1 0 with its shaft 13 in transverse position and projecting from bot-h ends of the motor. 1 1 are casters on the rear and under side of said motor base (see Fig. 2) and 15 is a T-shaped handle bar resembling a lawnmower handle and pivoted at its lower end on a transverse shaft 16 bearing in brackets 17 fixed on the top and rear part of the motor base 10 (see Figs l and 2) said handle normally extending upwardly and rearwardly as shown and its rearward position being determined by a stop bracket 17 fixed on the motor base (Fig. 2).

The floor contacting base of our device, hereinafter designated as the sanding base is of U-shape in general, said base having the parallel arms 18 in horizontal plane and grooved inwardly as 18 to slidably receive the tongues 10 of 'the motor base, said grooved runners extending toward the front or transverse end 19 of the base which is formed with a forwardly and downwardly directed face 19 From said front part 19 the sanding base rails 18 terminate in a transverse vertical face 19 said base plate 19 being cast or formed integral with the guides 18 and front end 19.

20 is an upright side frame on the 7 rear end of each guide 18, both bored at their top to receive the ends of a transverse cross'shaft 21, said bored part comprising a bifurcation of the upper side, and between the two parts of which is pivotally retained the rear end of a connecting rod 22. The front end of each said connecting rod comprises an eccentric strap 22 engaging a circular cam 23 fixed eocentrically on the adjacent extremity of motor shaft 13. 24 is a fly wheel fixed on shaft 13, one at each side of the motor and close to the eccentric, either of said fly wheels serving as a pulley for a belt 26 to drive the pulley 27 of a blower 28 which may be mounted on top of motor 11 as in Fig. 2. Said rotary blower has a suction tube 29 extending toward the front end of the sanding base and terminatesin a flat nozzle 29 arranged to suck in all dust at the front end of the sanding base, the blower exhausting such dust through a pipe 30 to any suitable receptacle (not shown).

In Fig. l-is shown that the sanding base is the widest part of our device, all moving parts being inwardly of its opposite longitudinal edges. 31 is a piece of sand paper secured flat against the under face of plate 19 by bending its rear edge part up against face 19" and securing the paper there by means such as a bar 32 clamping the paper against said face by means of screws 33, while the front edge of the paper is bent up and back to rest on face 19 and secured thereon by screws 34. The sand paper should of course be the full width of the device.

In Figs. 4 and 5, 35 is a sheet metal plate, bent upward at one edge to form a flan 35 and its opposite edge bent up and then back as 35 to engage respectively the rear and front parts 19*" and 19 of pad 19* and be secured thereto by the screws 3334 respectively, it being readily understood that this plate corresponds in shape and size to the sandpaper 31 when secured in place. 36 are transverse metal bars fixed on sheet 35 and having each downwardly directed cutting edges 36.

It will be readily seen that when either the sanding area of paper 31 or the scraper 35 36 are vibrated or oscillated longitudinally of the device a floor will be very rapidly cleared of old varnish, dirt, or unevenness. In Fig. 2 for example lines A and B designate the front and rear positions of the front part of the sand paper for each oscillation of the base, the front position A being very close to the wall WV but not actually touching the wall because of a transverse guard 37 fixed as at 38 on the front part of the motor base 10. The amount of vibration or oscillation is of course determined by the throw or eccentricity of cams 23 which oscillate the rods 22, side. frames 20 and the entire sanding base and frame. Although the entire weight of our device, in operation, is on the sandingbase, it is obvious that the greatest part of the weight is in the motor and its base, the handle 15 serving as a steadying and guiding device aiding in holding the motor and its base steady while the mot-or is running and the sanding means are oscillating. To transport the entire device from place to place the handle 15 is pressed back until the sanding area is clear of the floor and a the machine is supported on the casters let.

' pad with relation to the parallel arms of said frame, a motor supporting platform slidably mounted between said parallel arms, a motor .mounted on the forward part of said platform and having a shaft projecting from both ends, means operably connecting said shaft ends with the main frame for-rec1procoating the latter when the motor is running,

spacing means on the forward part of the platform to hold the device in spaced relation to a wall, and said main frame arranged to be reciprocated with the forward part of said pad limited to operate to a fixed distance from the wall, and means for securing a scraper element to said pad with said element contacting ith a floor, and a pivoted handle on said platform for guiding the device.

2. The structurespecified in claim 1, and said arms of the main frame normallysupported in spaced relation to a floor by said pad, and transporting means for the device comprising a caster fixedunder the rear end of each of said parallel arms and normally in non-contacting position with relation to the floor. I

3. The structure specified in claim'l, in which said pad of the main frame consists of a horizontal downwardly directed face member connecting the opposite rails of the said frame, and an upwardly and rearwardly di rectcd face extending transverselyof said pad across its front end and a vertical transverse face ext-ending transversely'across the rear end of said pad, and means in said transverse faces for removably securing a flat downwardly exposed scraper element thereto.

l. The structure specified in claim 1 in which said reciprocating means connecting the motor shaft ends to the reciprocable main frame comprises for each exposed end part of said shaft an eccentric cam disc fixed to the shaft, a cam strap engaging each said cam and a rod extending from the latter rearwardly, the rear end offeac-h said rod pivotally secured to the main frame. r

In testimony whereof we aflix our signatures. 1

JOSEPH E. GERETsoI-ILAEGER, FRANK P. CLARK; 

